Sr Trebuchet Challenge

Challenge Brief:-Design and build a medieval (or modern style) trebuchet to accurately hit a target from 50 meters-Projectile will be will a standard style water balloon-Target will be a standard size hula hoop

Requirements:

must be easily stored and fit through a doorway

safety is important!

a safety stop must be included to prevent accidental firing during loading or transportation

a pull mechanism must be included to launch (think of a pin from a grenade)

Your design should be modular and able to come apart for transportation (Nuts and bolts, etc

once finished assembly should take less than 5 minutes

a 'sight' for aiming your device

The counterweight of the trebuchet must be modular (able to take on and off)

But Weight! There's more!

We will be incorporating some modern designs and electronics into our project.I will be suppling some electronics parts that you must use for part of your projectWe have some Linear Actuators that would work great for helping with your safety release pins!

Materials and Design

You will be supplied with:

4 Pine 2x4s

1 2ft long solid round 1" diameter steel piece

1 2ft long solid round 1/2" diameter steel piece

wood screws and wood glue, fasteners up to $10 worth (average price of a nut or bolt is $0.50-$2 depending on size

Concrete mix to create your counterweight

TBA

​You supply:-rope-pouch/sling-anything else you want to add

Target Accuracy is important

Things to consider:​-side framework-Trebuchet Base-Runway length/style-Trebuchet Arm. How long will it be? Where will the fulcrum/axle be located? Details of the release pinVIRTUAL TREBUCHET . COM (click for calculation help!)​

If you want to do hand calculations to design a trebuchet with the best range, you will need to understand the physics involved. The picture below, shows a diagram of a trebuchet with the main parts labeled. The trebuchet relies on the principle that stored potential energy of the counterweight can be converted into kinetic energy of the payload, launching it into the air.

Wood Calculations:​1x1x1cm pine wood = .391grams

1inch cubed = 16.38cm cubed

A 12" (30cm) long piece of 3/4" x 3/4" pine is 0.1 lbs (43.4 grams)

Counterweight calculations:

Our Sample Weight is 1.8 pounds

Volume = 2.75×3×3.25 = 26.8125 inches3

Every inch cubed = 0.067 pounds

Therefore:

If you need 30 pounds of counterweight for your trebuchet the volume of cement required will be 446.7 inches3

Figure out what dimensions you may need to accomplish this.

Remember that you have a size requirement for your trebuchet. Your counterweight should not hit the ground or frame when in motion. It should be able to freely swing. You are getting a 24" long axle piece and need to account for the edges that are within the frame. Maybe you will only have 18" of width to fit a counterweight. Account for some wobble or motion so make a counterweight that fits!